A conventional dispensing system for applying hot melt adhesive generally includes a supply of adhesive material, a hot melt unit or melter that liquefies and heats the adhesive material to a desired application temperature, and at least one dispenser module or gun that selectively dispenses the heated adhesive onto a substrate. Furthermore, conventional dispensing systems generally include one or more controllers (e.g., a processor and a memory) and input controls electrically connected to the controller(s) to provide a user interface with the dispensing system. The controller(s) are in communication with the components of the dispensing system, such that the controller(s) control various aspects of the operation of the dispensing system. For example, the controller(s) may provide actuation signals to operate a solenoid valve in the gun, signals to adjust settings of the hot melt unit, and signals to prompt the delivery of more adhesive material from the adhesive supply to the hot melt unit.
In one particular type of conventional dispensing system, one of the controllers is a source of gun actuation, which may be a programmable logic controller, for example. This source of gun actuation is directly connected to the dispenser gun using a cable running between these components. In a similar manner, the hot melt unit is directly connected to the dispenser gun via a (typically heated) hose that is configured to supply molten adhesive to the dispenser gun following heating and melting at the hot melt unit. The hot melt unit includes a melter control system that is operable to monitor and control the elements within the hot melt unit. The melter control system of this conventional dispensing system does not communicate with or control the source of gun actuation.
As a result, multiple elements (e.g., cables and hoses) extend from the dispenser gun and create what may be considered an “unsightly” set of connections between the components of the dispensing system. In addition, these multiple separate cables and hoses effectively increase the size of a “gun envelope” defined by the space required for the dispenser gun and all wiring paths of hoses, cables, or other connectors that extend to other components directly connected to the dispenser gun. Especially in applications where the dispenser gun is mounted for movement with respect to a substrate, this larger gun envelope causes the cable(s) to encounter a higher risk of being accidentally interfered with or disconnected by adjacent personnel or equipment. Moreover, the melter control system operates effectively blindly with respect to the actuation signals being provided to the dispenser gun. In this regard, the melter control system can perform diagnostics and monitoring of components of the hot melt unit, but the melter control system does not receive signals that would enable similar diagnostics and monitoring of the components within the dispenser gun. This lack of “visibility” of the actuation signals for the dispenser gun makes it difficult to provide relevant diagnostic information on the entire dispensing system at a single user interface.
For reasons such as these, an improved dispensing system and method that enables more comprehensive diagnostics would be desirable.